Method and apparatus for controlling a multi-compressor air conditioning unit, air conditioning unit

Abstract

The application relates to the refrigeration technical field and discloses a method for controlling a multi-compressor air conditioning unit, the air conditioning unit being a water chiller unit, the air conditioning unit comprising compressors of multiple types, the maximum refrigerating capacities of the compressors of different types being different, the method comprising the following steps: in the case that the air conditioning unit is in refrigeration operation, obtaining a first difference value of a current outlet water temperature of the air conditioning unit and a target outlet water temperature, and a calibration quantity of the maximum refrigerating capacities of the compressors of different types; in the case that the first difference value is greater than a first threshold value, determining a target compressor to be loaded according to the first difference value, the calibration quantity and a second difference value of an inlet water temperature and an outlet water temperature of the air conditioning unit under full load conditions; and controlling the target compressor to start operation. According to the method, the target compressor can be determined relatively accurately and quickly when the compressors are loaded, the reliability of the air conditioning unit operation is improved, and the control precision is also improved. The application further discloses a device for controlling a multi-compressor air conditioning unit and an air conditioning unit.

Description

Technical Field

[0001] This application relates to the field of refrigeration technology, for example to a method, apparatus and air conditioning unit for controlling a multi-compressor air conditioning unit. Background Technology

[0002] Currently, when the actual water temperature of the chiller unit deviates from the target set water temperature, the unit controls the compressor to increase or decrease the number of compressor heads or adjust the energy load to bring the actual water temperature of the unit back to the set target water temperature.

[0003] A load control method for a multi-compressor unit is disclosed in the related technology, which acquires the outlet water temperature of the condenser cooling water and the return air temperature of the indoor unit in real time; if the outlet water temperature is within the start-up range and the return air temperature is greater than the set target temperature, the first compressor is started; the number of compressors to be loaded or unloaded is determined according to the difference between the real-time outlet water temperature, return air temperature and the target temperature.

[0004] In the process of implementing the embodiments of this disclosure, at least the following problems were found in the related art:

[0005] For chiller units with multiple compressors, if all compressors are of the same model (with the same maximum cooling capacity), any compressor can be selected to add or remove compressor heads. However, if the compressor models are different, randomly adding or removing compressor heads may cause the water temperature to fail to reach the target water temperature or far exceed the target water temperature, resulting in drastic fluctuations in system load. Summary of the Invention

[0006] To provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not intended as a general commentary, nor is it intended to identify key / important components or describe the scope of protection of these embodiments, but rather as a prelude to the detailed description that follows.

[0007] This disclosure provides a method, apparatus, and air conditioning unit for controlling a multi-compressor air conditioning unit to meet user target load requirements and improve the reliability of air conditioning unit operation.

[0008] In some embodiments, the air conditioning unit is a chiller unit, including multiple models of compressors, each model having a different maximum cooling capacity. The method includes: when the air conditioning unit is running, obtaining a first difference between the current outlet water temperature and the target outlet water temperature of the air conditioning unit, and a calibrated value of the maximum cooling capacity of each model of compressor; if the first difference is greater than a first threshold, determining the target compressor to be loaded based on the first difference, the calibrated value, and a second difference between the inlet water temperature and the outlet water temperature under full load conditions of the air conditioning unit; and controlling the target compressor to start operation.

[0009] In some embodiments, the apparatus includes a processor and a memory storing program instructions, the processor being configured to, when executing the program instructions, perform the aforementioned method for controlling a multi-compressor air conditioning unit.

[0010] In some embodiments, the air conditioning unit includes: a plurality of compressors of different models, each compressor having a different maximum cooling capacity; and, as described above, a device for controlling a multi-compressor air conditioning unit.

[0011] The method, apparatus, and air conditioning unit for controlling a multi-compressor air conditioning unit provided in this disclosure can achieve the following technical effects:

[0012] In this embodiment, a calibrated value for the maximum cooling capacity of different compressor models is obtained. A first difference between the detected current outlet water temperature and the target outlet water temperature is used to determine whether the air conditioning unit needs to be loaded. If the air conditioning unit needs to be loaded, the target compressor is determined based on the first difference, the calibrated value, and a second difference between the inlet and outlet water temperatures under full-load conditions. This allows for a more accurate and rapid determination of the target compressor when loading, ensuring the outlet water temperature reaches the target temperature. Simultaneously, this improves the reliability of the air conditioning unit operation and enhances control accuracy.

[0013] The above general description and the description below are exemplary and illustrative only and are not intended to limit this application. Attached Figure Description

[0014] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations and drawings do not constitute a limitation on the embodiments. Elements having the same reference numerals in the drawings are shown as similar elements. The drawings are not to be scaled. And wherein:

[0015] Figure 1 This is a schematic diagram of a method for controlling a multi-compressor air conditioning unit provided in an embodiment of this disclosure;

[0016] Figure 2 This is a schematic diagram of another method for controlling a multi-compressor air conditioning unit provided in an embodiment of this disclosure;

[0017] Figure 3 This is a schematic diagram of another method for controlling a multi-compressor air conditioning unit provided in an embodiment of this disclosure;

[0018] Figure 4 This is a schematic diagram of a method for determining a target compressor to be unloaded, as provided in the embodiments of this disclosure.

[0019] Figure 5This is a schematic diagram of a device for controlling a multi-compressor air conditioning unit provided in an embodiment of this disclosure;

[0020] Figure 6 This is a schematic diagram of another device for controlling a multi-compressor air conditioning unit provided in an embodiment of this disclosure. Detailed Implementation

[0021] To provide a more detailed understanding of the features and technical content of the embodiments of this disclosure, the implementation of the embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for illustrative purposes only and are not intended to limit the embodiments of this disclosure. In the following technical description, for ease of explanation, several details are used to provide a full understanding of the disclosed embodiments. However, one or more embodiments may still be implemented without these details. In other cases, well-known structures and devices may be simplified in their depiction to simplify the drawings.

[0022] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this disclosure described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0023] Unless otherwise stated, the term "multiple" means two or more.

[0024] In this embodiment of the disclosure, the character " / " indicates that the objects before and after it are in an "or" relationship. For example, A / B means: A or B.

[0025] The term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0026] The term "correspondence" can refer to an association or binding relationship. The correspondence between A and B means that there is an association or binding relationship between A and B.

[0027] In this embodiment, the air conditioning unit is a chiller unit, which includes a refrigerant system, a cooling water system, and a chilled water system. During cooling, the compressor in the refrigerant system drives the refrigerant to circulate between the condenser and the evaporator. The cooling water in the cooling water system carries away the heat generated by the condenser to the cooling tower, and the chilled water in the chilled water system circulates the cooling energy generated by the evaporator to the room, thereby achieving indoor cooling.

[0028] The chilled water outlet temperature of the chilled water system is detected. Based on the detected outlet temperature and the target outlet temperature, the air conditioning unit loads or unloads its output energy (referring to cooling capacity). When the air conditioning unit has multiple models of compressors, each with a different maximum cooling capacity, loading or unloading the air conditioning unit's energy refers to increasing or decreasing the number of compressor heads.

[0029] For example, consider a series of compressors with three models: A, B, and C. Model A has a cooling capacity of 150 RT, Model B has a cooling capacity of 200 RT, and Model C has a cooling capacity of 450 RT. If the maximum total cooling capacity of the air conditioning unit needs to be 600 RT, then there are three possible compressor combination schemes: Scheme 1: Using four model A compressors. Scheme 2: Using three model B compressors. Scheme 3: Using one model A compressor and one model C compressor. In Schemes 1 and 2, the compressors are all of the same model, simplifying energy control. However, the large number of compressor units results in lower costs. Scheme 3 offers the best cost, but the dispersed compressor models make energy control more difficult. Randomly adding or removing compressor units may cause the water temperature to either fail to reach the target temperature or exceed it significantly, leading to drastic fluctuations in system load.

[0030] Combination Figure 1 As shown, to address the difficulty in energy control of multi-compressor units, this disclosure provides a method for controlling multi-compressor air conditioning units, including:

[0031] S101, when the air conditioning unit is in cooling operation, the processor obtains the first difference between the current outlet water temperature and the target outlet water temperature of the air conditioning unit, as well as the calibrated value of the maximum cooling capacity of each type of compressor.

[0032] S102, if the first difference is greater than the first threshold, the processor determines the target compressor to be loaded based on the first difference, the calibrated quantity, and the second difference between the inlet water temperature and the outlet water temperature under full load conditions of the air conditioning unit.

[0033] S103, the processor controls the target compressor to start running.

[0034] When the air conditioning unit operates in cooling mode, the compressor runs to circulate the refrigerant. The cooling capacity generated by the evaporator is circulated to the indoor environment through chilled water to provide cooling for users. A temperature sensor is installed at the chilled water outlet to obtain the outlet water temperature of the air conditioning unit in real time. The current outlet water temperature is compared with the target outlet water temperature. Generally, if the current outlet water temperature is higher than the target outlet water temperature, it indicates that the indoor temperature is high. In this case, compressor load control may be required. If the current outlet water temperature is lower than the target outlet water temperature, it indicates that the indoor temperature is low. In this case, compressor load reduction control may be required.

[0035] Here, to avoid frequent compressor start-stop cycles, the first difference between the current outlet water temperature and the target outlet water temperature is obtained. When this first difference exceeds a first threshold, it indicates a significant difference between the current and target outlet water temperatures, requiring load control of the air conditioning unit. Then, based on the first difference, the second difference, and the calibrated maximum cooling capacity of each compressor model, the target compressor for loading is determined. The second difference refers to the difference between the inlet and outlet water temperatures under full-load conditions. The magnitude of the second difference depends on the total cooling capacity of the air conditioning unit and the operating frequency of the water pump. The calibrated maximum cooling capacity of each compressor model is stored on the air conditioning unit's local server or a cloud server. It can be retrieved from storage when needed.

[0036] The calibrated maximum cooling capacity of each compressor model refers to the recalibration of the maximum cooling capacity of each compressor model according to predetermined rules. As an example, the current air conditioning unit has a maximum total cooling capacity of 800 RT, including three compressors: model A (150 RT), model B (200 RT), and model C (450 RT). Using 100 RT as the smallest unit, the maximum cooling capacity of these three compressors is recalibrated. Therefore, the maximum cooling capacities of the three compressors are 1.5 * 100 RT, 2 * 100 RT, and 4.5 * 100 RT, respectively. This compressor calibration facilitates the air conditioning unit in identifying the target compressor and then controlling its operation to ensure the chilled water outlet temperature reaches the target outlet temperature.

[0037] In addition, it should be noted that if the compressor of the air conditioning unit is running at its maximum cooling capacity and the current outlet water temperature cannot reach the target outlet water temperature, the compressor will be loaded.

[0038] The method for controlling a multi-compressor air conditioning unit provided in this disclosure obtains a calibrated value for the maximum cooling capacity of different compressor models. By detecting a first difference between the current outlet water temperature and the target outlet water temperature, it is determined whether the air conditioning unit needs to be loaded. If the air conditioning unit needs to be loaded, the target compressor is determined based on the first difference, the calibrated value, and a second difference between the inlet water temperature and the outlet water temperature under full-load conditions. In this way, when loading the compressor, the target compressor can be determined relatively accurately and quickly through the calibrated value, ensuring that the outlet water temperature reaches the target temperature. Simultaneously, this improves the reliability of the air conditioning unit operation and enhances control accuracy.

[0039] Optionally, the water pump of the air conditioning unit is a variable frequency water pump. In step S102, the processor determines the second difference between the inlet water temperature and the outlet water temperature under full load conditions of the air conditioning unit in the following way:

[0040] The processor obtains the maximum total cooling capacity of the air conditioning unit and the water flow rate of the water pump under full load conditions.

[0041] The processor calculates ΔT2 = Q 总 / (L*A); where ΔT2 is the second difference, Q 总 The maximum total cooling capacity is given by L, where L is the water flow rate of the air conditioning unit under full load, and A is a constant.

[0042] Here, the air conditioning unit uses a variable frequency water pump. Under different operating conditions, the pump's operating frequency will vary, leading to different second differences in the inlet and outlet chilled water temperatures. Therefore, when using a variable frequency pump, it's necessary to obtain the air conditioning unit's maximum total cooling capacity and the water flow rate under full load. Then, based on the cooling capacity Q1 = L * ΔT2 * 1.163, the second difference can be derived. Here, 1.163 is a constant A, L is the water flow rate (unit: m³ / h), and ΔT2 is the second difference. 1 kW = 860 kcal, 1000 / 860 = 1.163.

[0043] Optionally, the water pump of the air conditioning unit is a fixed-frequency water pump. In step S102, the processor determines the second difference between the inlet water temperature and the outlet water temperature under full-load operation of the air conditioning unit in the following way:

[0044] The processor obtains the maximum total cooling capacity of the air conditioning unit and the rated flow rate of the fixed-frequency water pump.

[0045] The processor determines the second difference under full-load conditions of the current air conditioning unit based on the correspondence between cooling capacity, rated flow rate, and the second difference.

[0046] When the air conditioning unit uses a fixed-frequency water pump, obtain the rated flow rate of the fixed-frequency water pump and the maximum total cooling capacity of the air conditioning unit (i.e., the air conditioning unit is operating at full load). Obtain the corresponding second difference value by referring to a table. As an example, if the maximum total cooling capacity of the air conditioning unit is 800 RT and the fixed-frequency water pump is configured according to national standards, then the second difference value ΔT2 of the air conditioning unit is 5℃.

[0047] Optionally, in step S101, the processor obtains a calibrated value of the maximum cooling capacity of each compressor model, including:

[0048] The processor uses the compressor with the minimum maximum cooling capacity among all compressor models as a benchmark to calibrate the maximum cooling capacity of other compressor models.

[0049] The processor obtains the calibrated value Kn for each compressor model; where Kn = Qn / Q 准 Qn is the maximum cooling capacity of the nth compressor model, Q 准 This is the maximum cooling capacity of the reference compressor.

[0050] Here, the maximum cooling capacity of each compressor model is compared, and the compressor with the smallest maximum cooling capacity is used as the benchmark. The other compressor models are then calibrated using the maximum cooling capacity of the benchmark compressor to obtain calibration values. For example, the current air conditioning unit has a maximum total cooling capacity of 800 RT, including three compressors: model A (150 RT), model B (200 RT), and model C (450 RT). Using model A (the compressor with the smallest cooling capacity) as the benchmark, the other two compressor models are calibrated. That is, the cooling capacity of model B and model C is calibrated by multiplying the cooling capacity of the benchmark model A compressor by a correction factor. The cooling capacity of model B is calibrated as K2*200 RT, and the cooling capacity of model C is calibrated as K3*200 RT. The calibration values ​​are K2 = 1.3 and K3 = 3.

[0051] Combination Figure 2 As shown in the embodiments of this disclosure, another method for controlling a multi-compressor air conditioning unit is provided, including:

[0052] S101, when the air conditioning unit is in cooling operation, the processor obtains the first difference between the current outlet water temperature and the target outlet water temperature of the air conditioning unit, as well as the calibrated value of the maximum cooling capacity of each type of compressor.

[0053] S121, if the first difference is greater than the first threshold, the processor determines the target calibration value of the loaded compressor based on the first difference, the second difference between the inlet water temperature and the outlet water temperature under full load operation of the air conditioning unit, and the calibration value of each type of compressor.

[0054] S122, the processor determines the target compressor based on the target calibrated quantity.

[0055] S103, the processor controls the target compressor to start running.

[0056] Here, when loading the compressor, the target calibration value of the compressor is determined based on the first difference, the second difference, and the calibration value of each compressor model. Then, the target compressor is determined based on the target calibration value. For example, if the calculated target calibration value is 3, then for the 800RT air conditioning unit mentioned earlier, compressor model C can be identified as the target compressor. It should be noted that the target compressor refers to the compressor that is not currently running in the air conditioning unit. If compressor model C is already running, it cannot be identified as the target compressor. In this way, the calibration value simplifies the compressor control, making the control of multiple compressor models easier. Furthermore, the compressor selection method is more accurate and meets user needs, improving control precision.

[0057] Optionally, in step S121, the processor determines the target calibration value of the loaded compressor based on the first difference, the second difference between the inlet water temperature and the outlet water temperature under full-load operation of the air conditioning unit, and the calibration value of each compressor model, including:

[0058] The processor calculates Ks = (1 + K2 + ... + Kn) * ΔT1 / ΔT2.

[0059] Where Ks is the target calibration value, Kn is the calibration value of the nth model compressor, ΔT1 is the first difference, and ΔT2 is the second difference.

[0060] Here, the second difference is the difference between the inlet and outlet temperatures of the chilled water under full load (i.e., maximum total cooling capacity) conditions of the air conditioning unit. The ratio of the first difference to the second difference, multiplied by the sum of the rated values ​​of each compressor model, is the target rated value to be loaded. As an example, the air conditioning unit's water pump is a fixed-frequency water pump with a rated flow rate configured according to national standards, and the maximum total cooling capacity is 800RT. Then the second difference ΔT2 = 5℃. If the current outlet water temperature is detected to be 10℃ and the target outlet water temperature is 7℃, then the first difference ΔT1 = 3℃. Therefore, the target rated value Ks = (1 + 1.3 + 3) * 3 / 5 = 3.18. Then, the target compressor is selected according to the target rated value. For example, a C-type compressor can be selected, or a combination of a C-type compressor and an A-type compressor can be selected, or a combination of a C-type compressor and a B-type compressor can be selected.

[0061] Optionally, in step S122, the processor determines the target compressor based on the target quantity, including:

[0062] The processor compares the target calibration value with the calibration values ​​of various compressor models.

[0063] The processor selects the compressors corresponding to the calibrated values ​​as the target compressors to be loaded in descending order, and the sum of the calibrated values ​​of the target compressors is greater than or equal to the target calibrated value.

[0064] Here, after determining the target calibration value, it is compared with the calibration values ​​of each compressor model. Then, the target compressor is selected in descending order of value. As an example, the target calibration value is 3.18, the calibration value K1 of compressor model A is 1, the calibration value K2 of compressor model B is 1.3, and the calibration value K3 of compressor model C is 3. Therefore, 3.18 > K3 > K2 > K1. If compressor model C is not running, it is started first. If compressor model C is already running, compressor model B is started first. If both compressor models B and C are running, compressor model A is started. The air conditioning unit can also start multiple compressors simultaneously. If multiple compressors are not running, compressor models A and C, or compressor models B and C, can be started directly. In principle, the sum of the Kn values ​​of the loaded compressors should be greater than or equal to the target calibration value. In this way, when loading the compressor head, the air conditioning unit can achieve rapid adjustment and reduce the probability of compressor start-stop, improving the unit's control accuracy and compressor reliability. As another example, if the target calibration value is 2.8, then K3 > 2.8 > K2 > K1. If compressor C is not running at this time, compressor C will be started first. If compressor C is already running, compressor B will be started first. If both compressors B and C are running, compressor A will be started. Similarly, multiple compressors can be started simultaneously.

[0065] Combination Figure 3 As shown in the embodiments of this disclosure, another method for controlling a multi-compressor air conditioning unit is provided, including:

[0066] S101, when the air conditioning unit is in cooling operation, the processor obtains the first difference between the current outlet water temperature and the target outlet water temperature of the air conditioning unit, as well as the calibrated value of the maximum cooling capacity of each type of compressor.

[0067] S102, if the first difference is greater than the first threshold, the processor determines the target compressor to be loaded based on the first difference, the calibrated quantity, and the second difference between the inlet water temperature and the outlet water temperature under full load conditions of the air conditioning unit.

[0068] S103, the processor controls the target compressor to start running.

[0069] S204, if the first difference is less than the second threshold and the current outlet water temperature change rate is greater than the preset change rate, the processor determines the target compressor to be reduced based on the current outlet water temperature change rate and the preset change rate.

[0070] S205, the processor controls the shutdown of the target compressor.

[0071] This embodiment of the disclosure also includes compressor load reduction control. When the first difference between the current outlet water temperature and the target outlet water temperature is less than a second threshold, it indicates that the current outlet water temperature is lower than the target outlet water temperature, and the difference is significant. Further, the rate of change of the current outlet water temperature (i.e., the rate of water temperature decrease) is calculated. If the current rate of change of the current water temperature is greater than a preset rate of change, it indicates that the air conditioning unit needs to reduce the load on the compressor. The preset rate of change can be 0.04℃ / s. Then, based on the current rate of change of the outlet water temperature and the preset rate of change, the target compressor for load reduction is determined. Specifically, as described above, a target calibration value for load reduction can be determined based on the current rate of change of the outlet water temperature and the preset rate of change. Then, based on the target calibration value, the target compressor is determined.

[0072] like Figure 4 As shown, optionally, in step S204, the processor determines the target compressor for load reduction based on the current outlet water temperature change rate and a preset change rate, including:

[0073] S241, the processor calculates the ratio of the current rate of change of the outlet water temperature to the preset rate of change; and calculates the absolute value of the difference between each calibration quantity and the ratio.

[0074] S242, the processor uses the compressor with the calibrated quantity corresponding to the minimum absolute value of the difference as the target compressor for load reduction.

[0075] Here, the ratio of the current outlet water temperature change rate to the preset change rate is calculated. Then, the absolute value of the difference between the rated capacity and the ratio for each compressor model is calculated. These absolute values ​​are compared, and the compressor with the smallest absolute difference is selected as the target compressor for load reduction. For example, if the current outlet water temperature change rate is 0.05℃ / s and the preset change rate is 0.04℃ / s, the ratio is 1.25. The absolute value of the difference between the rated capacity and the ratio for compressor model A is 0.25, for model B it is 0.05, and for model C it is 1.75. The compressor model B, with the smallest absolute difference of 0.05, is selected as the target compressor for load reduction. In this way, the air conditioning unit can more quickly meet the user's actual target load and reach the target set temperature when adjusting the energy regulation load reduction head, reducing the probability of compressor start-stop and improving the unit's control accuracy and compressor reliability.

[0076] Combination Figure 5As shown, this embodiment of the disclosure provides an apparatus for controlling a multi-compressor air conditioning unit, including an acquisition module 51, a determination module 52, and a control module 53. The acquisition module 51 is configured to acquire, when the air conditioning unit is operating in cooling mode, a first difference between the current outlet water temperature and the target outlet water temperature of the air conditioning unit, and a calibrated value for the maximum cooling capacity of each compressor model. The determination module 52 is configured to, if the first difference is greater than a first threshold, determine the target compressor to be loaded based on the first difference, the calibrated value, and a second difference between the inlet water temperature and the outlet water temperature under full-load conditions of the air conditioning unit. The control module 53 is configured to control the target compressor to start operation.

[0077] The apparatus for controlling a multi-compressor air conditioning unit provided in this disclosure can obtain a calibrated value for the maximum cooling capacity of different compressor models. By detecting a first difference between the current outlet water temperature and the target outlet water temperature, it is determined whether the air conditioning unit needs to be loaded. If the air conditioning unit needs to be loaded, the target compressor is determined based on the first difference, the calibrated value, and a second difference between the inlet water temperature and the outlet water temperature under full-load conditions. In this way, when loading the compressor, the target compressor can be determined relatively accurately and quickly through the calibrated value, ensuring that the outlet water temperature reaches the target temperature. Simultaneously, this improves the reliability of the air conditioning unit operation and enhances control accuracy.

[0078] Combination Figure 6 As shown, this disclosure provides an apparatus for controlling a multi-compressor air conditioning unit, including a processor 100 and a memory 101. Optionally, the apparatus may further include a communication interface 102 and a bus 103. The processor 100, communication interface 102, and memory 101 can communicate with each other via the bus 103. The communication interface 102 can be used for information transmission. The processor 100 can call logical instructions in the memory 101 to execute the method for controlling a multi-compressor air conditioning unit described in the above embodiment.

[0079] Furthermore, the logic instructions in the aforementioned memory 101 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium.

[0080] The memory 101, as a computer-readable storage medium, can be used to store software programs and computer-executable programs, such as program instructions / modules corresponding to the methods in the embodiments of this disclosure. The processor 100 executes functional applications and data processing by running the program instructions / modules stored in the memory 101, that is, it implements the method for controlling a multi-compressor air conditioning unit in the above embodiments.

[0081] The memory 101 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created based on the use of the terminal device. Furthermore, the memory 101 may include high-speed random access memory and may also include non-volatile memory.

[0082] This disclosure provides an air conditioning unit that includes the above-described device for controlling a multi-compressor air conditioning unit.

[0083] This disclosure provides a storage medium storing computer-executable instructions configured to perform the above-described method for controlling a multi-compressor air conditioning unit.

[0084] The aforementioned storage medium can be a transient computer-readable storage medium or a non-transitory computer-readable storage medium.

[0085] The technical solutions of this disclosure can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes one or more instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in this disclosure. The aforementioned storage medium can be a non-transitory storage medium, including: a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and other media capable of storing program code; it can also be a transient storage medium.

[0086] The foregoing description and accompanying drawings fully illustrate embodiments of this disclosure to enable those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, procedural, and other changes. The embodiments represent only possible variations. Individual components and functions are optional unless explicitly required, and the order of operation may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. Moreover, the terminology used in this application is for describing embodiments only and is not intended to limit the claims. As used in the description of embodiments and claims, the singular forms “a,” “an,” and “the” are intended to equally include the plural forms unless the context clearly indicates otherwise. Similarly, the term “and / or” as used in this application means including one or more of the associated listed items and all possible combinations thereof. Additionally, when used in this application, the term "comprise" and its variations "comprises" and / or "comprising" refer to the presence of stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof. Without further limitations, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the process, method, or apparatus that includes said element. In this document, each embodiment may focus on the differences from other embodiments, and similar or identical parts between embodiments can be referred to mutually. For methods, products, etc., disclosed in the embodiments, if they correspond to the method section disclosed in the embodiments, the relevant parts can be referred to the description of the method section.

[0087] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the embodiments of this disclosure. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0088] The methods and products (including but not limited to devices and equipment) disclosed in the embodiments herein can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of units may be merely a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the shown or discussed units may be through some interfaces, and the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units may be selected to implement this embodiment according to actual needs. Furthermore, the functional units in the embodiments of this disclosure may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0089] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to embodiments of this disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than that shown in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. In the descriptions corresponding to the flowcharts and block diagrams in the accompanying drawings, the operations or steps corresponding to different blocks may also occur in a different order than disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. Each block in a block diagram and / or flowchart, and combinations of blocks in a block diagram and / or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

Claims

1. A method for controlling a multi-compressor air conditioning unit, characterized in that, The air conditioning unit is a chiller unit, comprising multiple models of compressors, each with a different maximum cooling capacity. The method includes: When the air conditioning unit is operating in cooling mode, obtain the first difference between the current outlet water temperature and the target outlet water temperature, as well as the calibration value of the maximum cooling capacity of each compressor model; wherein, using the compressor corresponding to the minimum maximum cooling capacity among the compressor models as the benchmark, calibrate the maximum cooling capacity of other compressor models; and obtain the calibration value Kn of each compressor model; Kn=Qn / Q 准 Qn is the maximum cooling capacity of the nth compressor model, Q 准 The maximum cooling capacity of the reference compressor; If the first difference is greater than the first threshold, the target compressor to be loaded is determined based on the first difference, the calibration value, and the second difference between the inlet water temperature and the outlet water temperature under full load conditions of the air conditioning unit; wherein, the target calibration value of the loaded compressor is calculated as Ks=(1+K2+…+Kn)×ΔT1 / ΔT2; Kn is the calibration value of the nth model compressor, ΔT1 is the first difference, and ΔT2 is the second difference; the target compressor to be loaded is determined based on the target calibration value. Control the target compressor to start running.

2. The method according to claim 1, characterized in that, The water pump of the air conditioning unit is a variable frequency water pump; the second difference between the inlet water temperature and the outlet water temperature under full load conditions of the air conditioning unit is determined by the following method: Obtain the maximum total cooling capacity of the air conditioning unit and the water flow rate of the water pump under full load conditions of the air conditioning unit; Calculate ΔT2=Q 总 / (L×A); Where ΔT2 is the second difference, Q 总 The maximum total cooling capacity is L, the water flow rate of the water pump under full load conditions of the air conditioning unit is L, and A is a constant.

3. The method according to claim 1, characterized in that, The step of determining the target compressor to be loaded based on the target calibration value includes: Compare the target calibration value with the calibration values ​​of various compressor models; The compressors corresponding to the standard values ​​are selected as the target compressors for loading, in descending order of size, and the sum of the standard values ​​of the target compressors is greater than or equal to the target standard value.

4. The method according to any one of claims 1 to 3, characterized in that, Also includes: If the first difference is less than the second threshold and the current outlet water temperature change rate is greater than the preset change rate, the target compressor for load reduction is determined based on the current outlet water temperature change rate and the preset change rate. Control the target compressor to shut down.

5. The method according to claim 4, characterized in that, The step of determining the target compressor for load reduction based on the current rate of change of outlet water temperature and a preset rate of change includes: Calculate the ratio of the current rate of change of the outlet water temperature to the preset rate of change; and calculate the absolute value of the difference between each calibrated quantity and the ratio. The compressor with the calibrated capacity corresponding to the minimum absolute value of the difference is used as the target compressor for load reduction.

6. An apparatus for controlling a multi-compressor air conditioning unit, comprising a processor and a memory storing program instructions, characterized in that, The processor is configured to, when executing the program instructions, perform the method for controlling a multi-compressor air conditioning unit as described in any one of claims 1 to 5.

7. An air conditioning unit, characterized in that, include: There are multiple models of compressors, each with a different maximum cooling capacity; and, The apparatus for controlling a multi-compressor air conditioning unit as described in claim 6.

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